Agnolo Gaddi. _Philadelphia, U.S.A.: J. G.
Johnson Collection_)]

And because in a certain manner there had come to Agnolo, by way of
inheritance, the secret of working in mosaic, and he had at home the
instruments and all the materials that his grandfather Gaddo had used in
this, he would make something in mosaic when it pleased him, merely to
pass time and by reason of that convenience of material, rather than for
aught else. Now, seeing that time had eaten away many of those marbles
that cover the eight faces of the roof of S. Giovanni, and that the damp
penetrating within had therefore spoilt much of the mosaic which Andrea
Tafi had wrought there at a former time, the Consuls of the Guild of
Merchants determined, to the end that the rest might not be spoilt, to
rebuild the greater part of that covering with marble, and in like
manner to have the mosaic restored. Wherefore, the direction and
commission for the whole being given to Agnolo, he, in the year 1346,
had it recovered with new marbles and the pieces laid over each other at
the joinings, with unexampled diligence, to the breadth of two fingers,
cutting each slab to the half of its thickness; then, joining them
together with cement made of mastic and wax melted together, he fitted
them with so great diligence that from that time onwards neither the
roof nor the vaulting has received any damage from the rains. Agnolo,
having afterwards restored the mosaic, brought it about by means of his
counsel and of a design very well conceived that there was rebuilt,
round the said church, all the upper cornice of marble below the roof,
in that form wherein it now remains; which cornice was much smaller than
it is and very commonplace. Under direction of the same man there was
also made the vaulting of the Great Hall of the Palace of the Podesta,
which before was directly under the roof, to the end that, besides the
adornment, fire might not again be able to do it damage, as it had done
a long time before. After this, by the counsel of Agnolo, there were
made round the said Palace the battlements that are there to-day, which
before were in no wise there.

The while that these works were executing, he did not desert his
painting entirely, and painted in distemper, in the panel that he made
for the high-altar of S. Pancrazio, Our Lady, S. John the Baptist, and
the Evangelist, and beside them the Saints Nereus, Archileus, and
Pancratius, brothers, with other Saints. But the